tolong jawab no 18 dan 20

No 18
24 = {1, 2, 3, 4, 6, 8, 12, 14}
46 = {1, 2, 23, 46}
72 = {1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72}

Faktor persekutuannya = {1, 2}

No 20
7,3(10) = 7,2(9) + x(1)
73 = 64,8 + x
x = 73 - 64,8
x = 8,2